My daughter first travelled to Europe 12 years ago. She was 23. We visited the Anne Frank House in Amsterdam which sparked her interest in WW2. She knew nothing of the Holocaust or concentration camps before that visit to Amsterdam. She bought several books from the shop there and when we got to Munich she asked to visit Dachau. So we did. It was just as you describe it. A desolate place but I’ve been told not nearly as bad as other camps. I can’t imagine anywhere worse. I’m happy that your friend was able to get out!